Many researchers continue to attempt to employ neurophysiologic techniques, such as electroencephalography (EEG), magnetic resonance imaging (MRI), functional magnetic resonance imaging (FMRI), positron emission tomography (PET), single photon emission computerized tomography (SPECT), as well as others, to guide therapeutic outcome in psychiatry. For example, the neurophysiologic technique of EEG measures the electrical activity of the brain as a function of time varying spontaneous potentials (SP) through a number of electrodes placed at standard locations on the scalp. The neurophysiologic information obtained through EEG analysis is recorded as sets of traces of the amplitude of SP referenced over time for scalp electrodes that are referenced electrically. This analog EEG information can then be visually analyzed and interpreted for signal abnormalities.
In the 1970's, quantitative analysis of the EEG signal provided rapid easy access to measurements that extended the EEG method beyond qualitative visual detection of signal abnormality. Quantitative EEG (QEEG) studies involve the multi-channel acquisition, processing, and analysis of brain activity often but not exclusively by computers. An example of an EEG/QEEG instrument is the Easy Writer II system, available from Caldwell Laboratories, Inc. (Kennewick, Wash.).
In one version of EEG/QEEG recordings, nineteen or more electrodes are commonly placed at standard locations on the scalp using the International 10/20 Placement System. A multi-channel recording of the brain's activity in an awake, eyes-closed, or “background” state is then recorded and analyzed often by use of Fast Fourier Transform (FFT) signal processing. Signal processing of the raw EEG permits measurement and quantification of multiple characteristics of brain electrical activity. In this process, artifacts due to muscle or eye movement or environmental noise are rejected, leaving only valid information suitable for further analysis.
Although technical and methodological guidelines for versions of EEG/QEEG extraction have been presented, studies that do not observe these essential guidelines are common. In addition to guideline non-conformance, the practice of ignoring the composite nature of psychiatric imbalances is commonplace. As a result, typical EEG/QEEG findings have not always been repeatable, and use of these versions of QEEG in psychiatric assessment and treatment is minimal.
Current behavioral definitions of psychiatric disorders do not correlate well with response patterns to medical treatment. Since psychiatric imbalances are behaviorally defined, they do not demonstrate a consistent relation with individual neurophysiological information, such as from EEG/QEEG or other neurophysiological techniques such as MRI, FMRI, PET, SPECT or other related techniques. However, if neurophysiological information were used as the independent variable and medication response is analyzed as the dependent variable, a connection between neurophysiology and the clinical outcome of treatment may be observed.
There is a need to develop clinical methods for using neurophysiological information as an independent variable and medication response as the dependent variable in order to probe the connection between neurophysiology and treatment outcome. Given such methods, the relationship between observed neurophysiologic abnormality, neurophysiologic intervention, and neurophysiologic treatment outcome in a given patient can be gauged.
There also is a need to develop a method for comparing quantified neurophysiologic information so that pattern differences between individual patients and reference groups can be catalogued and further, for classifying the neurophysiologic information of symptomatic patients according to anticipated treatment response and outcome measures.
There is a further need to develop a method for treating physiologic brain imbalances using neurophysiologic information. Supplemental to these treatment-associated needs, there is a need to develop a method for guiding clinical testing for new chemical, electrical, magnetic other interventions to treat physiologic brain imbalances, and for identifying new uses for known interventions.
Finally, there is a need to develop a method for the remote assessment and treatment of physiologic brain imbalances using neurophysiologic information.